Fighting Tactics and Forensic Awareness - Essay Example

FIRE INVESTIGATION Name Institution Professor Course Date Word Count (2017) Introduction Forensic awareness and fire fighting are crucial to a fire scene as they facilitate preservation of any proof that may be available. Fire is disparaging and fire fighting tactics have the potential to aggravate evidence loss. As a result, the origin of fire is an essential proposition that calls for a series of tests and steps in the course of fire investigation. Understanding the origin of fire helps in identifying the causes as well as the classification of fire. With respect to forensic fire investigation, the area of origin is identified as the structure or the geographical location within a scene of fire. The point of origin of fire, on the other hand, is the precise physical location within the area of origin. It is the point where a source of heat and the fuel meet leading to explosion or fire (NFPA, 2014). Causes of fire include terrorist attack, explosion, electric spark or arson. They can be deliberate, natural or accidental. This essay contends that fire fighting tactics and forensic awareness are crucial in the perseveration of evidence. The focus of the essay is on understanding fire dynamics, investigate techniques and fire suppression methods. The patterns and dynamic of fire is crucial as they help in determining the origin and cause of fire. Fire patterns entail the measurable or visible impacts that remain following occurrence of fire. According to Smith (1997), fire patterns includes the thermal impacts on materials such as oxidation, smoke, soot deposits, colour change, structural collapse, dissertation, consumption of combustibles and shifts in the affected material. Fire patterns is sometimes considered to include aspect such as energy release rate, heat transfer, pressure flows and gradients, ignition, development and spread of flame, toxicity, propagation, fire plume dynamics, fire modelling and enclosure dynamics ( Grimwood 2008). All these factors are utilised in the assessment of the origin and causes of fire (See Appendix 1). Based on the highlighted fire patterns, fire can take place in a closed compartment/room or in the open environment. The different sequence in flame spread and ignition depends on the type of fuel involved. Fire development with a room or compartment poses more problems to investigators of fire especially when a fire investigator seeks to determine the origin and cause of fire. According to NFPA (2014), it becomes challenging to the investigator to ascertain the origin and cause of fire when fire development reaches flashover. There are different phases that are involved when fire takes place in a room or a compartment (See Figure 1). Figure 1: Time and Temperature Curve Demonstrating the Stages of Fire Development Source: (Cooper 2015). According to the above figure, fire develops based on time. Any fire that takes place in an enclosed room must go through two stages, which include ignition and decay stages. The procedure in which fire undergoes flashover, post-flashover stages and full growth is reliant on numerous variables. These variables include type, quantity and organisation of fuels, the amount of available oxygen to be entrained by fire, the ventilation capabilities and size of the room besides the efficiency of both manual and automatic fire suppression (Bieber 2012; Grimwood 2008). Bieber (2015) claims that fire patterns analysis is linked to the presence of fuel or liquid accelerant. However, fire pattern analysis is mainly connected to flashover. Grimwood (2008) defines flashover as the change to a state of total surface engagement in a fire involving combustible materials with an enclosed compartment or room. Ceiling temperature in a compartment must reach heat flux (a measure of heat transfer) or 500°C-600°C(9320-11120F) while the floor of the room must reach 15-20kW/m2 (79.25Btu/min/ft2). Burning gases usually push out opening in a room such as windows and doors leading to other rooms at a considerable velocity when flashover takes place (Cooper 2015). Fire investigators and fighters encounter challenges when analysing and identifying flashover. It is usually hard to assess and determine the nature, timing, definition, conditions when fire takes place and frequency of occurrence of flashover. In this regard, fire fighters and investigators dread and sometimes stay away from flashover because of its harmful impacts on properties, physical evidences, evidences used to detect the origin and cause fire in a scene, and lives (Grimwood 2008). For instance, fire is sometimes started as a strategy of concealing evidence or murder. In such a situation, it is probable that the evidence or body will be totally destroyed as temperature gets to flashover or ascends to hundred degrees Celsius into two to three hours. This suggests that flashover takes place when fire develops from the source or the fuel package. Additionally, fire development in a room is linked to the room’s ventilation. This means that flashover is rapidly reached when the oxygen presence is sufficient. In this respect, fire investigators and fighters should comprehend that keeping windows, doors and other openings closed helps in preventing flashover. However, if a building contains insufficient ventilation, fire may get into the growth stage and fail to reach the peak heat release of a completely developed fire (See Figure 2). This procedure is known as hot-smouldering phase. Figure 2: Insufficient Ventilation in a Room against Heat Release Fire pattern in open place and flat setting, on the other hand, is different from fire in an enclosed room or compartment. According to David (2005), fire move outwards and towards any accessible fuel while producing hot gases above the fire. Notably, fire investigators cannot identify the cause of fire without first indentifying the origin of fire. Given that time is a key factor in the spread of fire, it is practical that quick and timely response by fire fighters facilitates prevention of flashover. Although time is crucial when preventing flashover, other factors are also worth considering. These factors include the ambient temperature at the start of the fire, rate of the fire development, the area, width, height, header height of open windows and doors or other openings for ventilation. It is also important to consider the amount of heat released or loss, the shape and size of the building, surface areas, materials and thickness thermal inertia of material, and the fire location within the building. The other factors to consider when assessing flashover include the active heating, ventilation, condition of the building and air (Avillo 2008). As regards the role of fire personnel, when fire takes place, fire fighters and police are the first to arrive at the scene of fire. As a result, they hold the distinctive prospect to scrutinize the fire behaviour. Notwithstanding that police and fire fighters are the first responders, their principle role is to save lives, extinguish the fire and protect property. However, the police and fire fighters should make observation of fire and offer helpful information to fire investigators upon their arrival, during the intial suppression stage, during overhaul activities and when they are en route to the scene of fire ( Smoke 2010). As first respondents to fire, police officers and fire fighters should observe the activities and conditions in the scene of fire mentally. All the written notes, video tapes and voice recordings should take account of information such as the colour amd direction of flame and smoke, the conditions of weather, use of the building, occupancy type, turned on lights, unsual odours and presence of containers. Other information that first responders to fire incidents should consider include the status of fire alarms, sprinklers, security alarms and the the type of fire suppression methods utilised. The supression techniques may include utility shufoff measures, forcible entry and ventilation (Reno et al. 2000). Other factors that fire fire fighters and police officers who are the first responders should consider and observe include fire patterns that include multiple fire locations, broken doors and windows burn injuries to victims, fire pattern in clothings, tire impressions, and shoes prints and discarded clothings. They should also observe and assess witnesses, victims and bystanders, empty containers, evidence of crime and weapons, drugs, clandstine drug laboratory and bodies, and presence of broken debris and glass ( Bieber 2012b). As regards factors affecting investigation, it is imperative to note that cognitive biasness and human error are major issues encountered while giving reports or taking notes on the activities and conditions of items scrutinized during incidences of fire. Cogntive biasness and human error undermine the trustworthiness of evidence presented and can make the observer to record or see something that was not an element of fire. More so, these aspects may make the observer fail to record or see things as they occured ( Bieber 2012b). Evidences on origin and cause of fire are often determined through scientific method, witness statements and physical evaluations. However, when making judgements, the court, prosecutors and fire investigators encounter problems in an occurrence where burn indicators and fire patterns are put at risk because of human misinterpretation regarding flashover, extensive overhauling and ceiling collpse (Bieber 2012b). The arson fire incidence highlighted in appendix 1 demonstrates that expectation bias was a total hinderance to fire fighters and investigators. The investigators maintained that Goerge Souliotes was a suspect with a intention. The fire investigators drew that conclusion because of the differing statements from different eye witnesses and biasness that included confirmation bias, role bias and selective re-examinaton bias that was as a result of the presence of a liquid accelerant in an ignitable liquid form demonstrated by the fire pattern. With respect to the preservation of evidence, physical evidence is an essential aspect of fire investigation. Therefore, fire personnel including fire investigators should strive to protect evidence in a fire scene. In this perspective, adequate fire suppression tactics and operations should be implemented to determine the cause and orign of fire ( Smith 1997). In this regard, excessive utilisation of water should be circumvented. This is because water can dilute ignitable liquid and damage, move or melt evidence in the scene of fire. Evidently, the presence of too much water can cause burnt paper, wood or matches to flow away from the original direction thereby destroying the evidence. For that reason, the utilisation of water in a fire scene should be controlled in a manner that it can be easily drained or should be utilised after fire investgators have assessed the scene ( Smith 1997). Smith (1997) stresses the need to prevent preventable damage while utilising straight-stream hoselines, breaking windows, knocking walls, when performing salvage and overhaul and when pulling ceilings. Excessive overhaul performed before the fire investigators have examined the scene can influence the outcome of investigation. Grimwood (2008) confirms that such an occurence prevents the investigators from determining the cause and origin of fire as well as the person accountable for the fire incident. Avoiding excessive overhaul before investigators’ examination is the best means to make sure that protection of the fire scene is for investigators to offer supervision in the course of the overhaul process. In addition, fire scene can be preserved through ensuring that no personnel apart from the investigators are working through the scene, isolation of areas or items containing evidence with ropes, sentries, barricades and barrier tapes and contamination of evidence ( Mauriell 2012). Ventilation is another essential aspect of fire fighting tactics. According to NFPA (2014), ventilation is essential in firefighting because it acts as a means of circumventing flashover and rescuing trapped occupants. However, ventilation is different in diverse fire scene. For instnce, more burned smoke build up leading to explosion when a large fire takes places in a room that has no adequate venilation. The heat created during this process causes flashover. In this perspective, a buiding should be horizontally or vertically ventilated to get rid of heat from the building. Conclusion Evidence can be compromised from the start to the supression process by the disparaging power of fire. While presevering evidence, avoiding flashover and creating ventilaton, the roles and responaibilites of fire personnel should be well understood. Given the increasing changes in building material and technology, fire fighters and investigators should take exhaustive steps to preserve evidence. Therefore fire fighting tactics and forensic awareness are crucial at the fire scene because they facilitate preservation of evidence. References Avillo, A 2008, Fireground Strategies 2nd edition, USA, PennWell. Bieber, P 2012, Fire Pattern Analysis and Case Study Review in Post-Flashover Fires.USA: Arson Research Project. Retrieved from https://www.google.co.uk/#q=case+study+of+arson+and+fire+dynamics Bieber, P 2012b, Case study review of cognitive bias in fire invetigation, USA, Arson Research Project. Cooper, G 2015, Gas Props for Training. Retrieved 11/ 12/2015, from http://www.tathrafirebrigade.org.au/index.php?option=com_content&view=category&id=12&Itemid=141 Daeid, N 2005, Fire investigation, Florida, CRC press. Grimwood, P 2008, Euro Firefighter. West Yorkshire: Jeremy Mills Publishing Ltd. Karlsson, B. A 2000, Enclosure fire, Florida, CRC Press. Mauriell, T. P 2012, Criminal Investigation Handbook (formerly Police Investigation Handbook), USA, Lexisnexis. Reno, J. M 2000. Fire and Arson Scene Evidence: A guide for public safety personnel, USA, National Institute of Justice. Smith, W. D 1997, The Firefighter's Role In Preserving The Fire Scene. FireEngineering, 150, vol.1, pp. 1-5. Smoke, C. H 2010, Company officer 3rd edition, USA, Delmar Cengage Learning. Appendix 1 Analysis of Case study of fire arson Adapted by (Bieber, 2012b) Read More